Ultrafast solid-state lithium ion conductor through alloying induced lattice softening of Li₆PS₅Cl

Abstract

A solid electrolyte with superb Li+ conductivity through tuning of the lattice chemistry in Li6PS5Cl. The ionic conductivity is enhanced through the combined effect of excess Li and substitution of S with Te.

Theoretical tuning of Ruddlesden–Popper type anti-perovskite phases as superb ion conductors and cathodes for solid sodium ion batteries

“…through mechanical alloying followed by power sintering. 35 However, the other two energetically stable compounds, Na 4 OCl 2 (I 4MMM(139)) and Na 4 OICl (P 4NMM(129)), are not dynamically stable, as exhibited in Fig. S1(a) and (b), † respectively.…”

“…Iso-valent replacement of Na with Li has also been investigated, on the basis of the DARP Na 4 S 0.5 O 0.5 I 2 phase, since rstly it has the widest temperature window for both energetic and dynamical stability, and secondly S substitution of O is expected to soen the lattice to induce improved ionic conductivity. 18,35 ATAT searching outcome for the stable congurations is represented as an convex hull, through the combination of DFT with cluster expansion simulation over…”

“…This is understandable, considering that stronger electrostatic attraction to the interlayer Cl À anions tends to keep Na + from hopping 20 Such signicant improvement of ionic conductivity through substitution of O with S is consistent with recent theoretical prediction and experimental conrmation that the reduced electrostatic attraction between S and alkali ions leads to lattice soening. 18,35 It is amazing to nd that in the case of the hybrid electrolyte Na 3 LiS 0.5 O 0.5 I 2 , the activation barrier in Na 23 Li 8 S 4 O 4 I 16 is reduced by a further half down to 0.12 eV, together with a remarkable Na + conductivity of up to 6.3 mS cm À1 (4.5 times of that in Na 11 Sn 2 PS 12 ). The very low activation energy also helps safeguard an ionic conductivity of 1.31 mS cm À1 at À50 C, which is extremely useful for a promising SSE.…”

“…Here in this work, we have carried out systematic modelling on the basis of a materials genome approach in the framework of density functional theory (DFT). 7,16,18,[33][34][35] On the basis of a high throughput simulation, we have identied effective routes for remarkable enhancement of ionic conductivity, based on Na 4 AX 2 (A ¼ chalcogen and X ¼ halogen). This covers the effects of smaller halogen anions on the X sites, substitution of O À2 with chalcogen species with weaker electronegativities on the A sites, and co-alloying on both the A and X sites.…”

Recent Development of Mg Ion Solid Electrolyte

“…Chalcogenide-based materials have been developed as solid conductors for Li ion and Na ion and have shown high ionic conductivity (Ramos et al, 2018;Xuan et al, 2018;Jia et al, 2019;Wang Y. et al, 2019). It is therefore highly interesting to develop chalcogenide-based ionic conductors for Mg ion.…”